1. Technical Field
This invention relates to a method and apparatus for producing hydrogen using geothermal energy, and more particularly, to a method and apparatus for producing hydrogen via electrolysis using geothermal energy.
2. Background of the Invention
Recently an increasing interest has been developing in methods of producing renewable energy that produces little or minimal pollution. One of the ways is using hydrogen to produce power or electricity. However, the methods of producing hydrogen at present are rather expensive and also can cause pollution.
U.S. Pat. No. 5,661,977 discloses a system for generation of electricity from geothermal energy wherein one or more substances are transported down a well to a depth at which geothermal heat (whether from brine or steam reservoirs or hot, dry rock) is sufficient to cause an endothermic reaction or an electrolysis reaction to occur among substances. In a second embodiment of the invention disclosed in this U.S. patent, a system is disclosed for the generation of electricity from geothermal energy wherein one juncture of a thermocouple is transported down a well to a depth at which geothermal heat is sufficient to create a temperature difference, relative to the temperature of the other juncture of the thermocouple. Such systems are rather complicated to construct so that the costs for constructing such system could be high.
Geothermal energy is conventionally produced using a constant flow rate of the geothermal fluid. Due to this, such a geothermal power plant operates at a fixed production level, while on the other hand, consumer power demand varies significantly between peak hours and off-peak hours. As a result, operation of such geothermal power plants is not cost effective.
As far as room temperature electrolysis operated at atmospheric pressure is concerned, the energy requirements are relatively high. Thus, electrolysis is a relatively expensive method of producing hydrogen.
Fouillac et al. (2003) discuss the use of geothermal heat to pre-heat the solution for high temperature (around 900° C. or more) electrolysis with additional energy sources such as coal- or gas-fired power being combined for such a use. In this paper, it is suggested that the geothermal energy could be combined with nuclear power plant energy.
It is therefore an object of the present invention to provide a new and improved method of and apparatus for producing hydrogen and operation of geothermal power plants wherein the disadvantages as outlined above are reduced or substantially overcome.